Post-tension cable wall stabilization

ABSTRACT

Provided herein are masonry structures, including walls, which are disposed upon a footing having a re-bar disposed longitudinally therethrough. The masonry structures of the invention include vertical bores disposed along their lengths, and include tensioned cables which extend through a first vertical bore, are spirally wound about the re-bar, and also extend through a second vertical bore such that the end portions are rigidly anchored in position near the top course of masonry units used in constructing the structures, and wherein the tensioned cables are under a relatively high mechanical tension. By staggering a plurality of tensioning cables, structures comprising a plurality of masonry units of enhanced structural stability over structures of prior art are provided.

TECHNICAL FIELD

This invention relates generally to architectural structures. More particularly, it relates to wall structures made from masonry materials, including natural stone, and to means for increasing the stability of such structures.

BACKGROUND

Wall structures made from masonry materials have been in use for centuries, with the famous Great Wall of China being a prime and popular example. Thus, it is well-known in the art to stack stones or like materials atop one another to provide wall structures, which structures may be from a few meters in length to several miles, and may vary in height from a few centimeters to several meters or more. Often, it is deemed desirable to employ a cementitious substance between layers of masonry materials such that the cementitious substance is in contact with successive layers and even between adjacent stone or masonry units, in order to add strength to the structure as a whole. For this use, mortars and grouts made from materials such as Portland cement and the like have been in widespread use even since Roman times, when the creation and use of a pozzolanic mixture of substance was first recorded.

Masonry units of a wide variety may be employed to construct a wall structure, including without limitation bricks and natural stones. Owing to their natural aesthetic value, natural stones are often a preferable choice for a person desirous of constructing a wall structure. Natural stones may be cut to any desired size and shape using lapidary or other known cutting equipment, thus the overall character of a finished wall structure is largely within the control of the builder.

Many workers in the prior art have realized that merely stacking stones atop one another to form a wall structure, even when grouts or mortars are employed to join the stones, does not yield a finished structure having as strong of structural integrity as is often perceived as necessary or desired. In order to add further strength, several workers have devised improved means for strengthening wall structures, many of which have been the subject of United States letters patent.

For example. as far back as 1906, Gerber taught in U.S. Pat. No. 829,397 a concrete fence having a plurality of ground blocks each provided with a vertical central bore and a projection on the top face, of a plurality of posts, each of which were provided with a vertical central bore and two lateral grooves and a recess in the bottom face, in which the projection of the respective ground block can engage. There were a plurality of plates adapted to engage in the grooves of the plurality of posts and a plurality of hold-down bolts passed through the vertical central bores of the plurality of ground blocks and the plurality of posts which were adapted to connect the fence together.

SUMMARY OF THE INVENTION

The present invention provides architectural structures comprising: a) a footing portion having a portion which extends in a substantially-linear direction; b) a re-bar disposed within the footing portion; c) a plurality of courses of masonry units stacked upon on e another so as to form a wall structure having a top course, bottom course, and a length dimension, the wall structure being disposed above the footing portion. A portion of the masonry units include a vertically-oriented bore disposed through them, and are arranged in a manner sufficient to provide a plurality of vertical bores extending through the wall structure at periodical distances along the length dimension of the wall. The vertical bores extend from the footing portion and through at least the 3 lowermost courses of masonry units of the wall structure. There are also a plurality of tensioning cables, wherein each tensioning cable comprises: a first end portion; a second end portion; and a mid portion. The tensioning cables each further comprise: i) a first vertical portion extending through one of the vertical bores; ii) a horizontal portion; and iii) a second vertical portion extending through a different one of the vertical bores than that of which first vertical portion extends. There are a plurality of cable anchoring means, with each cable anchoring means disposed within the wall structure at the top of each vertical bore through which a vertical portion of each tensioning cable extends. The first end portion and the second end portion of each of the tensioning cables is securely engaged with one of the cable anchoring means. In another embodiment, the horizontal portion of the tensioning cables includes a segment which is spirally-disposed about the re-bar. In a further embodiment, the footing is sub-terranean. In a further embodiment, the cable anchoring means are disposed within the penultimate course of the structure. In a further embodiment still, each of the tensioning cables are under a tension in the range of between about 3000 and 10,000 pounds, with a tension in the range of between about 7000 and 9000 being preferable, with a tension of about 8000 pounds being more preferable still.

The plurality of tensioning cables may be staggered, as shown, without limitation in FIGS. 4A and 4B herein. Thus the invention further provides an embodiment in which the plurality of tensioning cables includes a first tensioning cable and a second tensioning cable, wherein the first vertical portion of the second tensioning cable is disposed between both the first and the second vertical portions of the first tensioning cable. In yet another embodiment, the plurality of tensioning cables includes a first tensioning cable, a second tensioning cable, and a third tensioning cable, wherein the first vertical portion of the second tensioning cable and the first vertical portion of the third tensioning cable are disposed between both the first and the second vertical portions of the first tensioning cable.

BRIEF DESCRIPTION OF THE DRAWINGS

In the annexed drawings:

FIG. 1 shows a perspective view of a wall structure according to one form of the present invention;

FIG. 2 shows a cross-sectional view of the junction of a cable anchoring means with a masonry unit according to the prior art;

FIG. 3A shows a frontal view of a prior art wedge useful in anchoring a cable means in position according to the present invention;

FIG. 3B shows a side view of a prior art wedge useful in anchoring a cable means in position according to the present invention;

FIG. 4A shows a cable routing scheme in a wall structure according to one embodiment of the present invention;

FIG. 4B shows a cable routing scheme in a wall structure according to an alternate embodiment of the present invention; and

FIG. 5 shows a side view of how a hydraulic jack may be positioned when tensioning a cable in accordance with providing a tensioned wall construct according to the present invention.

DETAILED DESCRIPTION

Referring to the drawings and initially to FIG. 1 there is shown an architectural structure in accordance with one embodiment of the invention. In this FIG. 1 is shown a wall 10 that comprises a plurality of courses of masonry units 5 stacked upon one another, and which are also preferably provided with a conventional mortar or other binding substance in the interstices between the individual masonry units 5 and layers thereof.

The masonry units 5 may be any material from which wall structures are known in the art to be comprised, including without limitation: clay-based bricks; concrete blocks; pieces or sections of natural stone; composite materials; wood; ceramic tiles; poured concrete; and glass blocks, etc.

The wall 10 is preferably built upon a footing material 3, which in one preferred embodiment is a poured mortar or concrete, as such concretes as from which footing materials may be poured are well-known in the art. To provide such a footing, a trench is dug into the ground at the location upon which it is desired to erect the architectural structure.

Thus, the concrete footing material 3 has a length dimension, which coincides substantially with the course traveled by the wall structure 10. In a preferred embodiment, there is a metal reinforcing rod 7 (a.k.a. “rebar”) disposed within the interior of the bulk mass of the footing material 3. Such a structuring is readily accomplished by placing the reinforcing rod 7 in the trench, using support means such as wires, blocks, etc. (not shown) prior to pouring in the mortar or concrete footing material, as the use of such suitable supports are known in the art.

FIG. 1 also shows a desirable feature of the invention, which comprises a plurality of cable means A and B with each cable means having a vertical portion and a horizontal portion disposed within the overall inventive structure. The vertical portion of a cable means extends vertically through the vast majority of the courses of masonry units 5, in a via, which via in a preferred form of constructing such a wall structure 10 is provided by providing or drilling holes 21 through each of the masonry units 5 at the proper locations to permit alignment of such holes 21, prior to the assembly of the masonry units 5 to form the structure. Each of the cables inherently includes a first end portion and a second end portion, with the portion between the end portions being referred to herein as the mid-portion of the cable. Thus, the vertical portions of the cable means A and B exist within the confines of the wall structure 10 itself, in the via formed by the alignment of the holes 21 in each of the masonry units 5.

In a preferred form of the invention, the horizontal portions of the cable means A and B are in mechanical contact with the reinforcing rod 7, and it is especially preferred that the horizontal portions of the cable means A and B are wrapped around the reinforcing rod 7 , along the length of the reinforcing rod 7 in a spiral geometry. In one preferred embodiment, the structure is assembled and provided such that one of the vertical portions of the cable means B extends substantially vertically, and is disposed at a location that is between both of the vertical portions of the cable means A along the length dimension of the wall structure 10, to provide a staggered arrangement of the two separate cable means A and B.

Thus, the cable means A in FIG. 1 is shown to have a first end portion A₁ and a second end portion A₂, and the cable means B is shown to have a first end portion B₁ and a second end portion B₂. For these cable means, in one preferred embodiment, one of the end portions of the cable means is affixed in a stationary position to one of the masonry units 5 by a cable anchoring means 11 (FIG. 2), which may include an anchor plate or shoe, such as those shown in U.S. Patent Applications Nos. 2002/0007604, 2002/0129570, and 2004/0159058, the entire contents of which are herein incorporated by reference, or the SURE-LOCK® series of anchors sold by Precision Sure-Lock Company of Dallas, Tex. (http://www.precisionpt.com) , or GTI anchors sold by General Technologies, Inc. of Stafford Tex. (http://www.gti-usa.net) as such anchors are well-known in the art. However, it will be appreciated by one of ordinary skill in the art after reading and understanding this specification and the claims appended hereto that the use of any conventional anchoring means for anchoring a cable under tension which is functionally equivalent to those described above is with the metes and bounds of the present invention. In an alternate form of the invention, the means for anchoring a cable in a fixed location may include a hardware article having a hole in its construction, through which the cable means may pass and may further include a means for anchoring the cable in a stationary location in such hole, an example of which is seen in modem braking systems for bicycles. In another embodiment, the cable means may be welded to the anchor plate or shoe.

Regardless of which conventional means for anchoring the cable to the cable anchoring means is chosen, it will be necessary that the construct at the junction of the cable means and its anchoring means is overall larger than the hole through the masonry unit 5 through which the cable passes. The reason for this is that according to the invention, the vertical portions of the cable means A and B will later be caused to be placed under high tension, to provide a securing, stabilizing force to the wall structure 10.

Thus, for one embodiment where the first end portion A₁ of cable means A is equipped with a cable anchoring means at location 9 that is larger than the holes 21 in the masonry units, the second end portion A₂ of the cable means A is provided with a cable tensioning means at point 37. The cable tensioning means attached to the cable at point 37 may comprise any known means for tensioning a cable, including ratcheted wheels, winches, come-alongs, and hydraulic jacks, including those sold by Precision Sure-Lock Company under the SCJ, 5DA1, 6DA1, and PTJ series of products. Such a provision enables the constructor of such a wall structure 10 to apply tension to the cable A at its second end portion A₂, which, by virtue of the anchoring of the first end portion A₁ of the cable A by the cable anchoring means, causes increased stability and strength of the wall structure 10 as a whole. The cable means B may be similarly provided at each of its end portions with a cable tensioning means at location 39 at its second end portion B₂ and a cable anchoring means at B₁.

Although the cable anchoring means and cable tensioning means have been described herein in relation to certain preferred embodiments, a wide range of devices and means for securing cables and tensioning cables are known in the prior art. Thus, it is possible for one of ordinary skill to employ any such known means for anchoring and tensioning cables within a structure as described herein without deviating from the spirit and scope of the teachings of the present invention.

By staggering the vertical portions of each of the plurality of cable means, in FIG. 1 by having one vertical portion of cable means A in-between the two vertical portions of the cable means B, and by having one vertical portion of cable means B disposed in-between the two vertical portions of cable means A, a synergistic strengthening of the wall structure 10 as a whole is achieved.

In FIG. 2 is shown a cross-sectional view of the junction of a cable anchoring means 11 with a masonry unit 5, having a cable 20 disposed therethrough. Wedges 13 are shown in their position prior to their being positioned on the outer surface of the cable 20, and prior to their collectively being placed into the hole 69 of the cable anchoring means.

FIG. 3A shows a frontal view of a prior art wedge 13 useful in anchoring a cable means in position according to the present invention, having ridges 76 for increasing the holding force of the wedge against the cable, as is known in the art. FIG. 3B shows a side view of the prior art wedge 13 useful in securing a cable means in position according to the present invention.

The principle of the present invention of staggering the vertical portions of the cable means is extendible to a wide range of possible configurations. FIG. 4A shows a cross-sectional view of the schematic of the cable means described in the wall structure 10 from FIG. 1. From FIG. 4A it is apparent that there are two cable means in this section of wall, cable A and cable B, each having end portions A₁, A₂, and B₁, B₂, respectively, with one vertical portion of cable B being disposed between the two vertical portions of cable A, and wherein one vertical portion of cable A is disposed between the two vertical portions of cable B.

FIG. 4B shows an arrangement of cables within a length of wall section according to another embodiment of the invention, having five cables A, B, C, D, and E, each having end portions A₁, A₂, and B₁, B₂, and C₁, C₂, and D₁, D₂, and E₁, E₂, respectively. In this FIG. 4B the two vertical portions of a given cable include one vertical portion of each of two different cables, i.e., the cable means C includes a vertical portion of each of cables B and D between its vertical portions, and so on, as shown. Thus, the present invention provides wall structures which may include tensioned cable means that are staggered in a wide variety of configurations.

In FIG. 5 is shown a side view of how a hydraulic jack 41 may be positioned when tensioning a cable 20 in accordance with providing a tensioned wall construct according to the present invention. In this FIG. 5 is shown the masonry unit 5, cable anchoring means 11 having wedges 13 located in the hole 69 and disposed about the cable 20. The jack 41 (which can be any suitable mono-strand hydraulic ram jack, such as models in the series SJ2010 available from SPX Fluid Power Company of Rockford Ill. or equivalent products from Enerpac Corporation of Milwaukee, Wis.) is positioned in this figure above the cable anchoring means 11, with the spring portion 43 of the jack 41 facing the wedges 13. The cable 20 passes through the jack 41 where it exits near the gripping wedges 45. The gripping wedges 45 are placed in a receiving hole in the jack 41, and the jack is energized, by hydraulic power. This causes the gripping wedges 45 to pull the cable upwards, thus tensioning the cable to a desired tension. Then, the jack 41 is de-energized, and the cable then retracts downward into the masonry unit slightly, which pulls the wedges 13 down into the hole 69, thus engaging the cable 20 and keeping it in a tensioned condition. The gripping wedges 45 are recovered and re-used at a later time.

Although the cable anchoring means 11 may be located within a wall structure according to the invention at any position within a vertical bore, it is preferred that the anchoring means be disposed at the top portion of a given masonry unit 5. It is within the scope of the invention to dispose the anchoring portion at the top of the first course of masonry units. However, for greater stability, it is preferred that the anchoring means be disposed nearest the top of the wall as possible. In this regard it is especially preferable to dispose the anchoring means at a location which is at the top of the penultimate course of the structure. In such an embodiment, for aesthetics, a final top course may be applied over the anchoring means, thus obscuring them from view and providing a reinforced wall structure in which the reinforcement according to the invention is completely hidden from view.

Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations thereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto. This includes subject matter defined by any combination of any one of the various claims appended hereto with any one or more of the remaining claims, including the incorporation of the features and/or limitations of any dependent claim, singly or in combination with features and/or limitations of any one or more of the other dependent claims, with features and/or limitations of any one or more of the independent claims, with the remaining dependent claims in their original text being read and applied to any independent claims so modified. This also includes combination of the features and/or limitations of one or more of the independent claims with features and/or limitations of another independent claims to arrive at a modified independent claim, with the remaining dependent claims in their original text being read and applied to any independent claim so modified. Accordingly, the presently disclosed invention is intended to cover all such modifications and alterations, and is limited only by the scope of the claims which follow. 

1) An architectural structure comprising: a) a footing portion having a portion which extends in a substantially-linear direction; b) a re-bar disposed within said footing portion; c) a plurality of courses of masonry units stacked upon on e another so as to form a wall structure having a top course, bottom course, and a length dimension, said wall structure being disposed above said footing portion, wherein a portion of said masonry units each include a vertically-oriented bore disposed through them, and are arranged in a manner sufficient to provide, by the alignment of their individual bores, a plurality of vertical bores extending through said wall structure at periodical distances along the length dimension of said wall, said vertical bores extending from said footing portion and through at least the 3 lowermost courses of masonry units of said wall structure, d) a plurality of tensioning cables, wherein each tensioning cable comprises: a first end portion; a second end portion; and a mid portion, said tensioning cables each further comprising: i) a first vertical portion extending through one of said vertical bores; ii) a horizontal portion; and iii) a second vertical portion extending through a different one of said vertical bores than that of which first vertical portion extends; and e) a plurality of cable anchoring means, with each cable anchoring means disposed within said wall structure at the top of each vertical bore through which a vertical portion of each tensioning cable extends, wherein said first end portion and said second end portion of each of said tensioning cables is securely engaged with one of said cable anchoring means. 2) A structure according to claim 1 wherein said horizontal portion of said tensioning cables include a segment which is spirally-disposed about said re-bar. 3) A structure according to claim 1 wherein said footing is sub-terranean. 4) A structure according to claim 1 wherein said cable anchoring means are disposed within the penultimate course of said structure. 5) A structure according to claim 1 wherein each of said tensioning cables are under a tension which is any level of tension in the range of between about 3000 and 10,000 pounds. 6) A structure according to claim 1 wherein said plurality of tensioning cables includes a first tensioning cable and a second tensioning cable, wherein the first vertical portion of said second tensioning cable is disposed between both the first and the second vertical portions of said first tensioning cable. 7) A structure according to claim 1 wherein said plurality of tensioning cables includes a first tensioning cable, a second tensioning cable, and a third tensioning cable, wherein the first vertical portion of said second tensioning cable and the first vertical portion of said third tensioning cable are disposed between both the first and the second vertical portions of said first tensioning cable. 